1/*
  2 * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
  3 *
  4 * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
  5 * and DDR RAM to user space for applications interacting with PRUSS firmware
  6 *
  7 * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
  8 *
  9 * This program is free software; you can redistribute it and/or
 10 * modify it under the terms of the GNU General Public License as
 11 * published by the Free Software Foundation version 2.
 12 *
 13 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 14 * kind, whether express or implied; without even the implied warranty
 15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 */
 18#include <linux/device.h>
 19#include <linux/module.h>
 20#include <linux/moduleparam.h>
 21#include <linux/platform_device.h>
 22#include <linux/uio_driver.h>
 23#include <linux/platform_data/uio_pruss.h>
 24#include <linux/io.h>
 25#include <linux/clk.h>
 26#include <linux/dma-mapping.h>
 27#include <linux/slab.h>
 28#include <linux/genalloc.h>
 29
 30#define DRV_NAME "pruss_uio"
 31#define DRV_VERSION "1.0"
 32
 33static int sram_pool_sz = SZ_16K;
 34module_param(sram_pool_sz, int, 0);
 35MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
 36
 37static int extram_pool_sz = SZ_256K;
 38module_param(extram_pool_sz, int, 0);
 39MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
 40
 41/*
 42 * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
 43 * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
 44 * firmware and user space application, async notification from PRU firmware
 45 * to user space application
 46 * 3	PRU_EVTOUT0
 47 * 4	PRU_EVTOUT1
 48 * 5	PRU_EVTOUT2
 49 * 6	PRU_EVTOUT3
 50 * 7	PRU_EVTOUT4
 51 * 8	PRU_EVTOUT5
 52 * 9	PRU_EVTOUT6
 53 * 10	PRU_EVTOUT7
 54*/
 55#define MAX_PRUSS_EVT	8
 56
 57#define PINTC_HIDISR	0x0038
 58#define PINTC_HIPIR	0x0900
 59#define HIPIR_NOPEND	0x80000000
 60#define PINTC_HIER	0x1500
 61
 62struct uio_pruss_dev {
 63	struct uio_info *info;
 64	struct clk *pruss_clk;
 65	dma_addr_t sram_paddr;
 66	dma_addr_t ddr_paddr;
 67	void __iomem *prussio_vaddr;
 68	unsigned long sram_vaddr;
 69	void *ddr_vaddr;
 70	unsigned int hostirq_start;
 71	unsigned int pintc_base;
 72	struct gen_pool *sram_pool;
 73};
 74
 75static irqreturn_t pruss_handler(int irq, struct uio_info *info)
 76{
 77	struct uio_pruss_dev *gdev = info->priv;
 78	int intr_bit = (irq - gdev->hostirq_start + 2);
 79	int val, intr_mask = (1 << intr_bit);
 80	void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
 81	void __iomem *intren_reg = base + PINTC_HIER;
 82	void __iomem *intrdis_reg = base + PINTC_HIDISR;
 83	void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
 84
 85	val = ioread32(intren_reg);
 86	/* Is interrupt enabled and active ? */
 87	if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
 88		return IRQ_NONE;
 89	/* Disable interrupt */
 90	iowrite32(intr_bit, intrdis_reg);
 91	return IRQ_HANDLED;
 92}
 93
 94static void pruss_cleanup(struct platform_device *dev,
 95			struct uio_pruss_dev *gdev)
 96{
 97	int cnt;
 98	struct uio_info *p = gdev->info;
 99
100	for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
101		uio_unregister_device(p);
102		kfree(p->name);
103	}
104	iounmap(gdev->prussio_vaddr);
105	if (gdev->ddr_vaddr) {
106		dma_free_coherent(&dev->dev, extram_pool_sz, gdev->ddr_vaddr,
107			gdev->ddr_paddr);
108	}
109	if (gdev->sram_vaddr)
110		gen_pool_free(gdev->sram_pool,
111			      gdev->sram_vaddr,
112			      sram_pool_sz);
113	kfree(gdev->info);
114	clk_put(gdev->pruss_clk);
115	kfree(gdev);
116}
117
118static int pruss_probe(struct platform_device *dev)
119{
120	struct uio_info *p;
121	struct uio_pruss_dev *gdev;
122	struct resource *regs_prussio;
123	int ret = -ENODEV, cnt = 0, len;
124	struct uio_pruss_pdata *pdata = dev_get_platdata(&dev->dev);
125
126	gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
127	if (!gdev)
128		return -ENOMEM;
129
130	gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
131	if (!gdev->info) {
132		kfree(gdev);
133		return -ENOMEM;
134	}
135	/* Power on PRU in case its not done as part of boot-loader */
136	gdev->pruss_clk = clk_get(&dev->dev, "pruss");
137	if (IS_ERR(gdev->pruss_clk)) {
138		dev_err(&dev->dev, "Failed to get clock\n");
139		ret = PTR_ERR(gdev->pruss_clk);
140		kfree(gdev->info);
141		kfree(gdev);
142		return ret;
143	} else {
144		clk_enable(gdev->pruss_clk);
145	}
146
147	regs_prussio = platform_get_resource(dev, IORESOURCE_MEM, 0);
148	if (!regs_prussio) {
149		dev_err(&dev->dev, "No PRUSS I/O resource specified\n");
150		goto out_free;
151	}
152
153	if (!regs_prussio->start) {
154		dev_err(&dev->dev, "Invalid memory resource\n");
155		goto out_free;
156	}
157
158	if (pdata->sram_pool) {
159		gdev->sram_pool = pdata->sram_pool;
160		gdev->sram_vaddr =
161			(unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
162					sram_pool_sz, &gdev->sram_paddr);
163		if (!gdev->sram_vaddr) {
164			dev_err(&dev->dev, "Could not allocate SRAM pool\n");
165			goto out_free;
166		}
167	}
168
169	gdev->ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz,
170				&(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
171	if (!gdev->ddr_vaddr) {
172		dev_err(&dev->dev, "Could not allocate external memory\n");
173		goto out_free;
174	}
175
176	len = resource_size(regs_prussio);
177	gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
178	if (!gdev->prussio_vaddr) {
179		dev_err(&dev->dev, "Can't remap PRUSS I/O  address range\n");
180		goto out_free;
181	}
182
183	gdev->pintc_base = pdata->pintc_base;
184	gdev->hostirq_start = platform_get_irq(dev, 0);
185
186	for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
187		p->mem[0].addr = regs_prussio->start;
188		p->mem[0].size = resource_size(regs_prussio);
189		p->mem[0].memtype = UIO_MEM_PHYS;
190
191		p->mem[1].addr = gdev->sram_paddr;
192		p->mem[1].size = sram_pool_sz;
193		p->mem[1].memtype = UIO_MEM_PHYS;
194
195		p->mem[2].addr = gdev->ddr_paddr;
196		p->mem[2].size = extram_pool_sz;
197		p->mem[2].memtype = UIO_MEM_PHYS;
198
199		p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
200		p->version = DRV_VERSION;
201
202		/* Register PRUSS IRQ lines */
203		p->irq = gdev->hostirq_start + cnt;
204		p->handler = pruss_handler;
205		p->priv = gdev;
206
207		ret = uio_register_device(&dev->dev, p);
208		if (ret < 0)
209			goto out_free;
210	}
211
212	platform_set_drvdata(dev, gdev);
213	return 0;
214
215out_free:
216	pruss_cleanup(dev, gdev);
217	return ret;
218}
219
220static int pruss_remove(struct platform_device *dev)
221{
222	struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
223
224	pruss_cleanup(dev, gdev);
225	return 0;
226}
227
228static struct platform_driver pruss_driver = {
229	.probe = pruss_probe,
230	.remove = pruss_remove,
231	.driver = {
232		   .name = DRV_NAME,
233		   .owner = THIS_MODULE,
234		   },
235};
236
237module_platform_driver(pruss_driver);
238
239MODULE_LICENSE("GPL v2");
240MODULE_VERSION(DRV_VERSION);
241MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
242MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");